Have troop transports loaded with troop modules orbit a planet and capture it over time. The planet starts at 100% and over time the defender looses ground to the attacker as they capture more territory. Facilities and population can contribute to the defense percentage. If the attacking transports are destroyed the owner can use their own transports to recapture lost territory.

I find the idea quite distasteful, though giving it some thought it does have some merit. The way troops are handled are currently annoyingly demanding on player attention to handle properly, your suggestion WOULD solve it for both player and AI.

What I'd love would be if you got to assign a number of minimum troop units on any given planet so that they never get drained beneath that number, and so that it will automatically train new units until reaching that number, without tons of clicking.

You know, unless they implement that idea, I'd be quite happy with your idea. It wouldn't really reduce challenge as you can already bombard troop defenses away before invading. It would have to take a while regardless of how many transports you used though, otherwise it would be too easy.

Shadows is significantly focusing on making the troop aspect of the game more in depth, so I doubt Elliot will remove the troop mechanic to "increase performance and reduce micromanaging" as you request.

Have troop transports loaded with troop modules orbit a planet and capture it over time. The planet starts at 100% and over time the defender looses ground to the attacker as they capture more territory. Facilities and population can contribute to the defense percentage. If the attacking transports are destroyed the owner can use their own transports to recapture lost territory.

Sorry i can't see what is the big difference. Oh you mean the Troop modules stay at the Orbit, so the defender can shoot them even down ? Or do you got trouble to gather/transport the mass of troops are needed to conquer an enemy homeplanet ? Then you just want to drop one massive Troop module who do the job ?

Why not another Idea, When you blockade a planet with Ships/fleet, you can give the Order to start the Invasion. So long the Blockade stay up, the invasion continues. No Troops needed anymore.